20902189 has 16 divisors (see below), whose sum is σ = 26167680. Its totient is φ = 16220160.

The previous prime is 20902181. The next prime is 20902237. The reversal of 20902189 is 98120902.

It is not a de Polignac number, because 20902189 - 2³ = 20902181 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20902189.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20902181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26797 + ... + 27565.

It is an arithmetic number, because the mean of its divisors is an integer number (1635480).

Almost surely, 2^20902189 is an apocalyptic number.

It is an amenable number.

20902189 is a deficient number, since it is larger than the sum of its proper divisors (5265491).

20902189 is a wasteful number, since it uses less digits than its factorization.

20902189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1140.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 20902189 is about 4571.8911841819. The cubic root of 20902189 is about 275.4634125872.

It can be divided in two parts, 20 and 902189, that added together give a palindrome (902209).

The spelling of 20902189 in words is "twenty million, nine hundred two thousand, one hundred eighty-nine".